Machine for grinding watch-crystals.



H. A. BORRESEN.

MACHINE FOR GRINDING WATCH CRYSTALS.

APPLICATION 11,111) 001 14, 1907.

1,002,124. Patented Aug. 29, 1911.

COLUMBIA PLANOORAPH COHWASHIND'IOYL n. c.

HELGE A. BORRESEN, OF MARQUET'IE, MICHIGAN.

MACHINE FOR GRINDING WATCH-CRYSTALS.

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Specification of Letters Patent. Patented Aug, 2'9, 1911,

Application filed October 14,1907. SerialNo. 397,330.

To all whom it may concern:

Be it known that I, HnLen A. BORRESEN, a citizen. of the United States, and a resident of Marquette, in the county of Marquette and State of Michigan, have invented certain new and useful Improvements in Machines for Grinding IVatch-Crystals, of which the following is a full, clear, and exact description.

My invention relates to machines for grinding the circumferential edges of watchcrystals or the like, and its particular object is to provide means whereby the said crystals may be rigidly held in place on a turning lathe so that the danger of lateral movement of the same while in motion is positively avoided. In grinding watch-crystals special care must be taken to avoid this lateral movement of the same,because,owing to their fragile character, but a minute movement of the same out of its rotative plane will crack the crystal. This I accomplish by the means hereinafter fully described and as more particularly pointed out in the appended claims.

In the drawings: Figure 1 is a detail view inside elevation of a form of carrying out my invention. Fig. 2 is a transverse section thereof taken on line (l D, 3. Fig. 3 is a central vertical longitudinal section of the device illustrated in Fig. 1 showing an adjustable auxiliary friction disk. Fig. 4 is a detail perspective view of said auxiliary disk. Fig. 5 is a. perspective view of the locking nut used in connection with this type of machine.

Referring now to the figures I show a U shaped yoke having transversely abutting members adapted to hold the lens or crystal. This yoke is provided with a downwardly projecting screw threaded post 23 mounted in a. slot 24: on the platform as shown. This post is provided with a screw-threaded locknut for the purpose of locking and adjusting said yoke at various heights above the platform. This nut is provided with an operating handle, and has a. cam-face 26 preferably on its under side, the engagement of which cam with the sides of the slot are adapted to lock the post and yoke when the adjustment thereof has been completed.

In this type of grinding device provision is made for holding crystals of various diameters and to do this the non-slidable spindle 27 is preferably provided with a small disk 28 on its inner extremity that has a frictional surface. Between this disk and the bearings 29 of the spindle, and preferably slidable on and rotatable with said spindle, is a larger cup-shaped disk 30 the periphery of which has a friction-cushion 35 seated therein. The rear portion of this disk is formed into an integral sleeve 31 that is provided with diametrically opposite longitudinally elongated slots 32 that guide the longitudinal sliding movement of this sleeve by means of a pin 34 tapped transversely through the spindle. The end edge of this sleeve mediate said slots is preferably recessed as shown at 33 to form suitable seats for this pin when the larger disk is to be used. A coil-expansion spring 36 is wound around the spindle and its ends press against the disks 28 and 30 and normally keep the darger disk at the limit of its rearward movement. The cup-shaped disk 30 is so constructed that when the same is slid forward and the pin 34: seats in recesses 33 the face of said disk will be in a plane beyond the vertical plane of the face of the smaller disk 28 substantially as shown in Fig. 3 of the drawings, and a crystal placed between the face thereof and the head 37 of the plunger 38 will be securely held in po sition owing to the pressure exerted through a spring 39 back of said plunger.

While I have described my invention in connection with the grinding of watch-crystals it is of course understood that the said machine is readily applicable for the pur pose of grinding disks of various materials,

lenses for eye-glasses, microscopes, and the like, without departing from the spirit of my invent-ion.

What I claim as new is 1. A device for holding crystals to be ground, comprising a substantially U-shaped yoke having transversely disposed hearings in the upper ends of the longitudinal me1nbers thereof, spindles mounted in said bearings, one of which is slidable longitudinally toward and from the other, friction disks mounted upon said non-slidable spindle, means for advancing one of said disks in front of the other, and means secured to the other spindle between which and one of said disks the article to be ground is held.

2. A device for holding crystals to be ground, comprising asubstantially U-shaped yoke having transversely disposed bearings in the upper ends of the longitudinal members thereof, spindles mounted in said bearings one of which is slidable longitudinally toward and from the other, a friction disk mounted on the end of said non-slidable spindle, an auxiliary friction disk movable longitudinally on said non-slidable spindle, means for advancing said auxiliary disk beyond the plane of the face of said first-mentioned disk, and means secured to the other spindle between which and one of said friction disks the article to be ground is held.

3. A device for holding crystals to be ground, comprising a substantially U-shaped yoke having transversely disposed bearings in the upper ends of the longitudinal members thereof, spindles mounted in said bearings one of which is slidable longitudinally toward and from the other, a friction disk mounted on the end of said non-slidable spindle, an auxiliary friction disk movable longitudinally on said non-slidable spindle, a spring for advancing said auxiliary disk beyond the plane of the face of said firstmentioned disk, and means secured to the other spindle between which and one of said friction disks the article to be ground is held.

4:. A device for holding crystals to be ground, comprising a substantially U-shaped yoke having transversely disposed bearings in the upper ends of the longitudinal members thereof, spindles mounted in said bearings one of which is slidable longitudinally toward and from the other, a friction disk mounted on the end of said non-slidable spindle, an auxiliary friction disk movable longitudinally on said non-slidable spindle, a coil-spring between said friction disks and normally pressing said auxiliary disk away from said first-mentioned disk, and means secured to the other spindle between which and one of said friction disks the article to be ground is held.

5. A device for holding crystals to be ground, comprising a substantially U-shaped yoke having transversely disposed bearings in the upper ends of the longitudinal members thereof, spindles mounted in said bearings one of which is slidable longitudinally toward and from the other, a friction disk mounted on the end of said non-slidable spindle, an auxiliary friction disk movable longitudinally on saidnon-slidable spindle, means for advancing said auxiliary disk beyond the plane of the face of said first-mentioned disk, and a head on the end of said slidable spindle between which and one of said friction disks the article to be ground is held.

6. A device for holding crystals to be ground, comprising a substantially U-shaped yoke having transversely disposed bearings in the upper ends of the longitudinal members thereof, spindles mounted in said bearings one of which is slidable longitudinally toward and from the other, a friction disk mounted on the end of said non-slidable spindle, an auxiliary disk movable longitudinally on said non-slidable spindle, a spring between said disks and normally pressing said auxiliary disk away from said firstmentioned disk, means for holding said auxiliary disk at the limit of its forward movement againstthe tension of said spring, and means secured to the opposite spindle between which and one of said friction disks the article to be ground is held.

7. A device for holding crystals to be ground, comprising a substantially U-shaped yoke having transversely disposed bearings in the upper ends of the longitudinal members thereof, spindles mounted in said bearings one of which is slidable longitudinally toward and from the other, a friction disk mounted on the end of said non-slidable spindle, an auxiliary disk movable longitudinally on said spindle, a spring between said disks for normally pressing said auxiliary disk away from said first-mentioned disk, means for holding said auxiliary disk at the limit of its forward movement against the tension of said spring, and a head rotatable on said opposite spindle between which and one of said disks the article to be ground is held.

8. A device for holding crystals to be ground comprising a substantially U shaped yoke having transversely disposed bearings in the upper ends of the longitudinal members thereof, spindles mounted in said bearings one of which is slidable longitudinally toward and away from the other, a friction disk mounted upon one of said spindles, and means secured to the other spindle between which and said disk the article to be ground is held. a

In testimony whereof I have hereunto set my hand and seal this 2d day of October,

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

